Deuteronomy 18:21
And if you say in your hearts, How are we to be certain that the word does not come from the Lord?
1 Thessalonians 5:24
God, by whom you have been marked out in his purpose, is unchanging and will make it complete.
1 John 4:1-3
My loved ones, do not put your faith in every spirit, but put them to the test, to see if they are from God: because a great number of false prophets have gone out into the world.
Revelation 2:2
I have knowledge of your doings, and of your hard work and long waiting, and that you will not put up with evil men, and have put to the test those who say they are Apostles and are not, and have seen that they are false;